Constant flow valve



1952 c. D. BRANSON CONSTANT FLOW VALVE Filed April 19, 1948 After 72.835

w e w m .4. Charles Patented Feb. 1952 coNs'rANT FLow VALVE Charles D. BransonQKnoxville, Tenn., assignor to I Robertshaw-Fulton Controls Company, Knoxville, Tenn.,-a corporation of Delaware Application April '19, 1948, Serial No. 21,799

' v5 Claims.

This invention relates to valves for providing a constant flow of fluid in pipes and other passages irrespective of changes in fluid pressure in the pipe or passage. I Y I It is a well known physical theorem that a constant flow of fluid through an orifice of fixed size is obtained when the pressure differential across such an orifice is constant. This theorem has been utilized in various mechanical devices for obtaining a constant flow of fluid through a fixed orifice by adjusting the pressure on the discharge side of i the orifice to compensate for pressure changes on the supply side of the orifice to maintain a constant differential therebetween. -In cer-' tain of these devices a pressure responsive means such as a corrugated expansible and contractible metallic vessel is subjected tethe pressures on the supply side of the'orifice and actuates a valve on the discharge side of the orifice. An increase of pressure on the'supply side of the orifice actuates such means to throttle down its associated valve to increase the pressure on'the discharge side of the orifice to maintain the pres sure diflferential across the orifice constant. The reverse or this action occurs when the 'pres' sure on the supply side of the orifice decreases and the pressure on' the discharge side is decreased commensurately to maintain themes-- Pistons, 'diaphragms sure differential constant. and othersimilar mechanical devsices-have also been employed in place of the corrugated vessel,-

and in certain installations the. discharge pressures have been employed to modulate supply pressures to maintain the desired constantpres sure difierential. t r

All of these prior devices have been subject to-certaindisadvantages either in" uniformity of operation, complexity of construction, liu'llkiness,v

jAnotherobject is to provide. such a valve which is of I positive; certain and uniform operation.

Another object isto provide such a valve which is of simple construction.

Another object is to provide such a valve which iscompact and cheap to manufacture.

(Cl. 137--152)v 2 Another object is to provide such a valve which has a minimum of maintenance requirementsand' costs.

Another object is to provide such a valve which will act as a check valv'e'of the poppet type when the pressure on the supply side of the orifice falls below a predetermined minimum or it may be a double seated poppet type valve.

Another object is to provide such a valve which is readily adapted for a wide variety of types of installations wherein a constant flow of fluid is desired. Y

Other and further objects of the'present invention will appear from the following description.

My invention is capable of various mechanical embodiments two of which are shown in the accompanying drawing and are described hereinafter to illustrate the same. These illustrative Fig. 8 is a cross section of the embodimentof Big. 1 on the line 3-3 thereof; and

Fig. 4 is a cross section of the embodiment of Fig. 2 on the line 44 thereof.

Referring now more particularly to Figs. 1 and 3; a suitable supply pipe I!) for fluid under pressure is shown as expanded at shoulder l I to provide an enlarged cylindrical chamber I 2. Discharge pipe I3 is connected to chamber I2 'by any a suitable coupling l4. Discharge pipe I3 as H lustrated is reduced in diameter at l5 to form a cylindrical extension [6 closed at its end I I. One or more openings I8 are'provided in extension It at any suitable location, here shown as adjacent its base. A tubular sleeve valve member I9 surrounds extension I6 and is free to reciprocate thereon. Valve member [9 is shown as closed at 20 and has a disk 2! suitably secured thereto as by a rivet 22.

chosen that disk 2| can move an appreciable distance away from shoulder II before the areas Member I9 has one or more, apertures 23. beneath disk 2!. an'cl is'ofsuch a of openings |8 are affected and thereafter it will cooperate with said openings within the expected give the desired pressure drop across the orifice as will appear from the ensuing explanation.

Disk 2| is shown as having a loose fit in chamber l2, its clearance therein being so chosen as to provide an orifice 25 of desired constant area, but as will be apparent the disk may be guided in said chamber and the orifice provided in any other suitable way.

With this embodiment of my invention organized as described, when the fluid in pipe Ill is under a pressure less than the pressure of spring 24, spring 24 will urge disk 2| into en-v gagement with shoulder H to act as a poppet valve effectively sealing pipe I0. Disk 2| will continue to act as a check valve until the fluid pressure in pipe I0 exceeds the strength of spring 24. At this time disk 2| will move away from shoulder H and open orifice 25, allowing fluid under pressure to pass through orifice 25 and enter the space between member l9 and the wall of chamber |2 whence it will pass through the apertures 23 to exert a uniform pressure on the under surface of disk 2|. Disk 2| continues to move down against the tension of spring 24 until the pressure exerted on theupper surface of disk 24 is equal and opposite to the pressure acting on the under surface of disk 2| plus the force exerted by spring 24. In this position the open end of valve member l9 has been moved into cooperative relationship with the openings l8 and is conditioned to vary the eiiective area thereof upon variations in the pressure of the fluid flowing to and through the orifice 25. As the fluid pressures acting on the opposite sides of disk 2| are equal and opposite so that disk 2| is acting as a balanced valve member", it is apparent that the pressure differential across orifice 25 is determined by the force exerted by spring 24. Movement of disk 2| on increases of pressure in pipe l0 will move member Hi ,to decrease the effective area of openings |8,.r'apidly.. building up the pressure exerted on the underside of diaphragm 2| and countering the increase of pressure in pipe II] to balance the fluid pressures on said disk and thereby maintainlthe pressure difierential across orifice 25, at.;that value which is determined by spring 24. When the pressure drops in pipe l0, spring 24 willforcef disk 2| and member l9 upwardly, increasing the effective area of the openings l8 to reduce the pressure on the underside of disk 2| and counter the decrease of pressure in pipe I0, again balancing .the fluid pressures on the disk 2| so as to maintain the pressure differential across orifice 25 at that value which is determined by spring 24.

The embodiment of Figs. 2 and 4 functions in exactly the same manner as described for the embodiment of Fig. 1. When controlling the fiow of fluids containing impurities or other" granular material which might lodgebetween extension I6 and valve member IS with the danger'that the action of the valve might be modified or destroyed it is advisable to allow an increased clearance between these elements. To

provide this clearance and prevent chattering of 4 i the elements element I9 is shown as of increased diameter with respect to extension l6 and the openings l8 are peened outwardly at 26 to slidingly engage member I9.

While in the embodiment illustrated the pressure on the discharge side of the orifice 25 is shown as admitted to the underside of the disk through apertures 23 in the valve member l9, it will be apparent to those skilled in the art that any other suitable construction may be used in order that the fluid pressure at the discharge side of said orifice be applied to the side of disk 2| which is opposite that subjected to the supply pressure so as to secure the balance of fluid pressures whereby the valve will operate as herein explained. It will also be apparent that if desired a second seat for the disk 2| may be provided so that it may function as a double of the orifice to maintain a constant pressure.

differential across'the orifice; which is of positive, certain and uniform operation; which is of simple construction; which is compact and.

cheap to manufacture; which requires minimum maintenance and has minimum maintenance costs; which acts as a check valve, and which is readily adapted for use in a widevariety of systems requiring a constant flow of fluid.

Changes to or modifications of the above described illustrative embodiment of my invention may now be suggested to those skilled in the art without departing from my inventive concept.

Reference should therefore behad to the appended claims to determine the scope of this invention.

What is claimed is:

1. In a constant flow control valve, a supply pipe, a discharge pipe, a valve housing connect ,ing said pipes, a closed extension of said discharge pipe in said housing in communication; with said housing through a ported side, a valve element surrounding said extension and mounted for reciprocation thereon to vary the efiective ;area of the port in said extension, a disk in thesupply side of said housing secured to the end of said element and providing a predetermined orifice between its periphery and the Walls of said housing, said disk having at opposite sides there- 'of substantially equal areas respectively sub- 2. In a constant flow control valve, a supply pipe, a discharge pipe, a valve housing connecting said pipes, a disk mounted for reciprocation in the supply side of said housing and providing a constant area orifice between its periphery and the walls of said housing, said disk having substantially equal areas at the opposite sides thereof subjected respectively to the supply and discharge pressures, a sleeve valve element con nected tosaid disk, ,ja ported member in communication with said discharge pipe and with which said sleeve valveelement cooperates by reciprocation thereon, and resilient means for urging said disk toward said supply pipe.

3. A control valve as described in claim 2 in 5 which said sleeve valve element is ported adjacent the underside of said disk to equalize fluid pressures acting thereon.

4. A control valve as described in claim 2 in which the ports of said member in communication with said discharge pipe have outwardly extending edges to bear against said sleeve.

5. In a constant flow control valve, a supply pipe, a discharge pipe, a valve housing connect- 1 ing said pipes, a closed extension of said discharge pipe in said housing in communication with said housing through a ported side, a sleeve slidably mounted on said extension for reciprocation thereon to vary the effective area of the port in said extension, a disk operatively connected to said sleeve for reciprocable movement therewith and disposed in the supply side of said housing, said disk providing a constant area orifiee between its periphery and the walls of said 6 housing and having substantially equal areas at the opposite sides thereof respectively subjected to the supply and discharge pressures, and resilient means for urging said disk toward said supply pipe.

CHARLES D. BRANSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 780,986 Francis Jan. 31, 1905 1,579,251 Schossow Apr. 6, 1926 1,933,852 Hahn Nov. '7, 1933 2,069,022 Sisk Jan. 26, 1937 2,307,949 Philips Jan. 12, 1943 2,321,573 Chase June 15, 1943 

